Biomedical subjects
T Imai
Publications and source records attributed to T Imai.
[Effects of long-term ethanol intake on the bone mass on femoral bone of mice: a microdensitometrical study].
This report on the effects of ethanol intake on bone tissue in ICR strain mice. The authors let male and female ICR mice take 16% ethanol solution (Sake) ad lib for 472 days beginning at the age of 38 days. Observations were using radiograph on bone density of hind legs, we were measured at the middle of the femur densitometer. The effects of indices. Observations were carried out on bone density were analyzed using six indices: the maximum density of the middle of the bone cortex (h1, h2) (the maximum density of the bone cortex (h1 + h2)/2 [hmax]); the minimum density of the middle of the bone marrow (h3) (minimum density of the bone marrow [hmin]); the bone cortical width (d1 + d2); the bone marrow width (d); the cortical bone index (the ratio of cortical bone width to bone width [CBI]); and the radial trabecular index (the ratio of bone width to hmin [RTI]). The results were as follows: In male mice, hmax, hmin, d1 + d2, CBI and RTI were significantly lower than controls (p < 0.01, p < 0.01, p < 0.01, p < 0.01, p < 0.05). In females, hmax, hmin, d1 + d2 and CBI were significantly lower than controls (p < 0.01, p < 0.01, p < 0.01, p < 0.05). The number of osteocytes in the femur diaphysis did not significantly differ between groups. These findings suggest that ethanol intake affects kidney tissues, and decreased reabsorption of calcium were caused by damaging the kidneys, thereby increasing excretion of Ca to the urine. Bone resorption occurred in order to homeostasis of Ca concentration in blood.
Parotid gland papillary cystadenocarcinoma in a Fischer 344 rat.
A spontaneous parotid gland tumor with histomorphologic features characteristic of cystic and papillary growth was found in a 72-week-old F344 rat. The tumor had a prominent cystic appearance and invasive growth into the dermis beyond the muscular layer of the skin. The cyst walls were lined by a single layer of cuboidal to tall columnar epithelium with prominent papillary projections continuous with the cyst lining. The tumor cells had mucoid, pale cytoplasm and medium to large nuclei. The myoepithelium did not appear to be associated with the tumor cysts and the papillae. Atrophic parotid gland tissues were seen between cysts and in the periphery of the cystic lesions. In light of these findings, the tumor was diagnosed as papillary cystadenocarcinoma of parotid gland; this is the first description of a salivary gland papillary cystadenocarcinoma in a rat.
[Clinical significance of a multiple myeloma cell line, derived from a case associated with hyperammonemia].
Recently, there have been several reports describing patients with multiple myeloma complicated by consciousness disturbance due to hyperammonemia. Here we report a patient with multiple myeloma and hyperammonemia, who died after rapid progression of the disease. A 71-year-old man who had been diagnosed as having Bence Jones protein (kappa)-type multiple myeloma in 1996 was readmitted to our hospital in February 1997 because of worsening bone pain, renal dysfunction, and hypercalcemia. Bone marrow aspiration yielded an almost dry tap, and the bone marrow was found to be completely occupied by immature plasma cells. Although liver dysfunction was slight, the serum ammonia level was high and increased gradually. Despite treatment, the patient died due to cerebral embolism and progression of plasmacytic leukemia in October 1997. Peripheral blood sampled at the time of death showed a serum ammonia level of 204 micrograms/dl, and the myeloma calls were cultured using monolayered bone marrow stromal cells as feeder cells. This led to the successful establishment of a cell line. The level of ammonia in the supernatant was high, indicating that the cultured myeloma cells produced and released ammonia.
Successful treatment of disseminated Fusarium infection in an infant with leukemia.
Disseminated Fusarium infection in an immunocompromised host is intractable and results in high mortality. We provide the first full case report on successful treatment of a disseminated Fusarium infection in an infant. The 6-month-old infant, whose family raised livestock, had infantile leukemia. During the neutropenic period after intensive chemotherapy, vomiting, diarrhea, fever, subcutaneous nodes, and coughing appeared. Pneumonia was diagnosed, and Fusarium moniliforme was isolated from blood culture. A central venous catheter was removed. Granulocyte colony-stimulating factor (G-CSF) and amphotericin B (AMPH-B) (total dose, 65 mg/kg) were administered continuously for 8 weeks. The infection was resolved according to improvement of clinical and laboratory findings, and intensive chemotherapy was restarted for the leukemia. Cord blood stem cell transplantation from an unrelated donor was performed. The Fusarium infection did not recur, but after transplantation, leukemia relapsed. Treatment of neutrophils using G-CSF, AMPH-B, and local treatment induced resolution of the disseminated Fusarium infection in this immunocompromised host with malignancy. We suggest caution for patients living in an environment conducive to the development of Fusarium infection because of the particular risk of infection.
Successful engraftment of allogeneic peripheral blood stem cell transplant after nonmyeloablative preparative regimen with cytarabine and cyclophosphamide: report of 2 cases.
We report our experience with allogeneic peripheral blood stem cell transplantation (allo-PBSCT) following a nonmyeloablative conditioning regimen consisting of cytarabine (8 g/m2) and cyclophosphamide (120 mg/kg) in the treatment of 2 patients aged 50 and 55 years with refractory chronic myelomonocytic leukemia and chronic myeloid leukemia in accelerated phase, respectively. Our nonmyeloablative regimen was well tolerated by older patients at high risk of regimen-related toxicity by the conventional conditioning regimen but was immunosuppressive enough to achieve mixed chimerism. After allo-PBSCT, we monitored chimerism in these patients by fluorescence in situ hybridization using X- and Y-specific probes and polymerase chain reaction-based analysis of a variable number of tandem repeats. We found that full chimerism and graft-versus-leukemia (GVL) effects could be induced in these patients by donor lymphocyte infusions and withdrawal of posttransplantation immunosuppressive therapy. Our observations suggest that a nonmyeloablative conditioning regimen can establish mixed chimerism and that donor lymphocyte infusion may induce GVL effects in older patients at high risk of regimen-related toxicity.
[Physiological monitoring in the new century(discussion)].
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[Increase in serum creatine phosphokinase following administration of talipexole hydrochloride].
We presented a 60-year-old man with a 12 year history of Parkinson's disease. The wearing-off phenomenon occurred 3 years after starting L-dopa. The patient was admitted to this unit in order to readjust his medication Administration of talipexole hydrochloride was initiated, the patient complained of an aggravation of Parkinsonism, and increases in serum creatine phosphokinase (CK) levels to 1,875 IU/l was observed. The dosage of talipexole was gradually reduced and the drug was ultimately discontinued since incomplete neuroleptic malignant syndrome was suspected. Serum CK levels then gradually decreased and returned to normal. Literature retrieval revealed two cases of neuroleptic malignant syndrome following administration of bromocriptine mesilate. Therefore, neuroleptic malignant syndrome should be considered when initiation of dopamine agonist worsens Parkinsonism.
Fact-finding survey of actual garbage discharged from dormitory and its biological anaerobic-aerobic treatment.
The objective of this study is to find a possibility of complete treatment of garbage and resource recovery (production of methane from available utility of carbon resource in garbage) by biological treatment process. As the first step, a fact-finding survey of actual garbage discharged from the dormitory of the Ube National College of Technology (equivalent to 300 population) was carried out. Second, the combined biological anaerobic-aerobic treatment, i.e. combination of upflow anaerobic sludge blanket (UASB) process and aerobic membrane bioreactor (AMB) process, was applied to the garbage treatment. The applicability and efficiency of this system were investigated in this study. The survey results showed that the composition and quantity of garbage from a student dormitory changed slightly during a week due to the change of the menu, however, they remained almost unchanged during the entire experimental period. The experimental results showed high biodegradability of the garbage, and demonstrated its suitability for methane production. The soluble nitrogen removal was high: over 97%. No excess sludge was wasted from the system. A high treatment efficiency of simultaneous organic carbon and nitrogen was obtained. The possibility of complete treatment of garbage with this process has been positively demonstrated by this study.
Synergistic transcriptional activation by hGABP and select members of the activation transcription factor/cAMP response element-binding protein family.
The Ets-related DNA-binding protein human GA-binding protein (hGABP) alpha interacts with the four ankyrin-type repeats of hGABPbeta to form an hGABP tetrameric complex that stimulates transcription through the adenovirus early 4 (E4) promoter. Using co-transfection assays, this study demonstrated that the hGABP complex mediated efficient activation of transcription from E4 promoter synergistically with activating transcription factor (ATF) 1 or cAMP response element-binding protein (CREB), but not ATF2/CRE-BP1. This synergy also partially occurred when hGABPalpha was used alone in place of the combination of hGABPalpha and hGABPbeta. hGABP activated an artificial promoter containing only ATF/CREB-binding sites under coexistence of ATF1 or CREB. Consistent with these results, physical interactions of hGABPalpha with ATF1 or CREB were observed in vitro. Functional domain analyses of the physical interactions revealed that the amino-terminal region of hGABPalpha bound to the DNA-binding domain of ATF1, which resulted in the formation of ternary complexes composed of ATF1, hGABPalpha, and hGABPbeta. In contrast to hGABPalpha, hGABPbeta did not significantly interact with ATF1 and CREB. Taken together, these results indicate that hGABP functionally interacts with selective members of the ATF/CREB family, and also suggest that synergy results from multiple interactions which mediate stabilization of large complexes within the regulatory elements of the promoter region, including DNA-binding and non-DNA-binding factors.
The role of human MBF1 as a transcriptional coactivator.
Multiprotein bridging factor 1 (MBF1) is a coactivator which mediates transcriptional activation by interconnecting the general transcription factor TATA element-binding protein and gene-specific activators such as the Drosophila nuclear receptor FTZ-F1 or the yeast basic leucine zipper protein GCN4. The human homolog of MBF1 (hMBF1) has been identified but its function, especially in transcription, remains unclear. Here we report the cDNA cloning and functional analysis of hMBF1. Two isoforms, which we term hMBF1alpha and hMBF1beta, have been identified. hMBF1alpha mRNA was detected in a number of tissues, whereas hMBF1beta exhibited tissue-specific expression. Both isoforms bound to TBP and Ad4BP/SF-1, a mammalian counterpart of FTZ-F1, and mediated Ad4BP/SF-1-dependent transcriptional activation. While hMBF1 was detected in the cytoplasm by immunostaining, coexpression of the nuclear protein Ad4BP/SF-1 with hMBF1 induced accumulation of hMBF1 in the nucleus, suggesting that hMBF1 is localized in the nucleus through its binding to Ad4BP/SF-1. hMBF1 also bound to ATF1, a member of the basic leucine zipper protein family, and mediated its activity as a transcriptional activator. These data establish that the coactivator MBF1 is functionally conserved in eukaryotes.
Enhanced HIV-1 replication by chemokines constitutively expressed in secondary lymphoid tissues.
Persistent infection of human immunodeficiency virus (HIV) takes place in the secondary lymphoid tissues even during clinically latent stages. The CC chemokines secondary lymphoid tissue chemokine (SLC) and EBI1-ligand chemokine (ELC) are constitutively expressed in the secondary lymphoid tissues. They share CCR7 expressed on lymphocytes and mature dendritic cells and play key roles in the trafficking of these types of cells into the secondary lymphoid tissues. Here we report that growth of both X4 and R5 strains of HIV-1 in activated peripheral blood T cells was enhanced by SLC. The enhancing effect of SLC was abrogated by pretreatment of cells with pertussis toxin, indicating the involvement of signaling via a receptor coupled with a Galphai class of G-protein. Furthermore, SLC was found to enhance the promoter activity of HIV-1 LTR. These results suggest that signaling via CCR7 has a strong positive effect on HIV growth. Thus, SLC and ELC may contribute to persistent infection of HIV in the secondary lymphoid tissues by promoting viral replication in activated T cells.
Molecular cloning of a novel CC chemokine, interleukin-11 receptor alpha-locus chemokine (ILC), which is located on chromosome 9p13 and a potential homologue of a CC chemokine encoded by molluscum contagiosum virus.
Molluscum contagiosum virus (MCV) encodes a CC chemokine MC148R which is likely to have been acquired from the host. By a homology search employing MC148R as a probe, we have identified a novel CC chemokine whose gene exists next to the IL-11 receptor alpha (IL-11Ralpha) gene in both humans and mice. Thus, this chemokine maps to chromosome 9p13 in humans where IL-11Ralpha has been assigned. We term this novel chemokine IL-11Ralpha-locus chemokine (ILC). ILC has the highest homology to MC148R among the known human CC chemokines. Furthermore, ILC is strongly and selectively expressed in the skin where infection of MCV also takes place. Thus, ILC is likely to be the original chemokine of MC148R.
Improving the pharmacokinetic and pharmacodynamic properties of a drug by chemical conversion to a chimera drug.
The purpose of the present study is to investigate a new concept which involves the conjugation of two drugs having different pharmacological activities which is termed a 'chimera drug (mutual prodrug)', in drug delivery optimization using a chemical modification approach. The conjugates of FP, an NSAID, with histamine H(2) antagonists were synthesized, in order to investigate the reduction in gastric damage by NSAID, and their pharmaceutical, pharmacokinetic and pharmacological properties were examined. The limited data obtained herein indicate that the chimera drug composed of FP and PPA was effective in reducing gastric damage by FP, with no changes in its biopharmaceutical properties, compared with the conventional prodrugs such as ester-type prodrugs.
Biological differences between reflux stimulated proliferative stomal lesions and N-methyl-N'-nitro-N-nitrosoguanidine induced carcinomas in Wistar rats.
The morphology and evolution of epithelial lesions that developed at a gastrojejunal stoma due to reflux of duodenal contents were compared with MNNG-induced carcinomas in the pyloric mucosa of rats in a long term experiment. Random bred male Wistar rats were given MNNG in drinking water (100 mg/l) for 12 weeks and then one group was submitted to a gastrojejunal anastomosis at the greater curvature in the oxyntic mucosa. Untreated rats underwent either gastrojejunostomy or gastrotomy. The animals were killed at the 24th and 66th weeks of the experiment. The lesions obtained in the pyloric mucosa and in the mucosa of the gastrojejunal stoma were analyzed histologically using hematoxylin and eosin staining and immunohistochemistry for pepsinogen isoenzyme 1. Duodenal reflux induced proliferative lesions at the gastrojejunal junction that increased in incidence and size with time. Histologically they consisted of benign epithelial proliferation of gastric type. No evidence of malignant transformation within the gastric components of the proliferative lesions at the gastrojejunal stoma was observed even at the 66th week. Adenocarcinomas induced by MNNG in the pyloric mucosa increased in size during the experiment and were morphologically and histochemically distinct from the proliferative lesions at the gastrojejunal junction. In conclusion, proliferative lesions at the gastrojejunal stoma stimulated by duodenal reflux are biologically distinct from adenocarcinomas induced by MNNG in the pyloric mucosa. They do not seem to be precursor lesions of gastric carcinogenesis, as they do not undergo malignant transformation even after long-term, up to 66 weeks, follow-up.
Molecular cloning of a novel human CC chemokine (Eotaxin-3) that is a functional ligand of CC chemokine receptor 3.
Previously, we mapped the novel CC chemokine myeloid progenitor inhibitory factor 2 (MPIF-2)/eotaxin-2 to chromosome 7q11.23 (Nomiyama, H., Osborne, L. R., Imai, T., Kusuda, J., Miura, R., Tsui, L.-C., and Yoshie, O. (1998) Genomics 49, 339-340). Since chemokine genes tend to be clustered, unknown chemokines may be present in the vicinity of those mapped to new chromosomal loci. Prompted by this hypothesis, we analyzed the genomic region containing the gene for MPIF-2/eotaxin-2 (SCYA24) and have identified a novel CC chemokine termed eotaxin-3. The genes for MPIF-2/eotaxin-2 (SCYA24) and eotaxin-3 (SCYA26) are localized within a region of approximately 40 kilobases. By Northern blot analysis, eotaxin-3 mRNA was constitutively expressed in the heart and ovary. We have generated recombinant eotaxin-3 in a baculovirus expression system. Eotaxin-3 induced transient calcium mobilization specifically in CC chemokine receptor 3 (CCR3)-expressing L1.2 cells with an EC(50) of 3 nM. Eotaxin-3 competed the binding of (125)I-eotaxin to CCR3-expressing L1.2 cells with an IC(50) of 13 nM. Eotaxin-3 was chemotactic for normal peripheral blood eosinophils and basophils at high concentrations. Collectively, eotaxin-3 is yet another functional ligand for CCR3. The potency of eotaxin-3 as a CCR3 ligand seems, however, to be approximately 10-fold less than that of eotaxin. Identification of eotaxin-3 will further promote our understanding of the control of eosinophil trafficking and other CCR3-mediated biological phenomena. The strategy used in this study may also be applicable to identification of other unknown chemokine genes.
An activation-responsive element in single C motif-1/lymphotactin promoter is a site of constitutive and inducible DNA-protein interactions involving nuclear factor of activated T cell.
Single C motif-1 (SCM-1)/lymphotactin is a C-type chemokine whose expression is activation dependent, cyclosporin A sensitive and restricted to CD8+ T cells, double-negative thymocytes, gammadelta-type T cells, and NK cells. In humans, there are two highly homologous genes encoding SCM-1alpha and SCM-1beta. Here we examined the regulatory mechanism of the SCM-1 genes. The luciferase reporter gene under the control of the 5' flanking region of 0.7 kb was strongly induced upon activation with anti-CD3 or PHA plus PMA only in SCM-1-producer T cell lines through a cyclosporin A-sensitive mechanism. An element termed E1 located at -108 to -95 nt relative to the major transcription start site was found to be critical for the promoter activity. In electrophoretic mobility shift assays using the E1 oligonucleotide as probe, nuclear extracts from unstimulated T and B cell lines formed a constitutive complex termed complex I, while nuclear extracts from stimulated SCM-1-producer T cell lines formed a higher mobility complex termed complex II with a concomitant decrease in complex I. The shift from complex I to complex II seen only in SCM-1-producer T cell lines upon activation was completely suppressed by cyclosporin A. Both complexes were critically dependent on the NF-AT core sequence TTTCC in the E1 element and were partially supershifted by anti-NF-ATp. One-hybrid assays in yeast isolated NF-ATp as an E1 binding protein, and transfection of NF-ATp into T and B cell lines strongly enhanced the activation-dependent SCM-1 promoter activity. Collectively, a unique mechanism involving NF-ATp appears to regulate the cell type-specific and activation-dependent expression of the SCM-1 genes.
Molecular cloning of mXCR1, the murine SCM-1/lymphotactin receptor.
Single C motif-1 (SCM-1)/lymphotactin is a C-type member of the chemokine superfamily. Previously, we identified its specific receptor XCR1. Here we isolated the murine homologue of XCR1 (mXCR1). To demonstrate its biological activity, we produced recombinant mouse SCM-1 by the baculovirus expression system. B300-19 murine pre-B cells expressing mXCR1 responded to mSCM-1 in chemotactic and calcium-mobilization assays. mXCR1 mRNA was weakly expressed in spleen and lung of normal C57BL/6 mice. In spleen, CD8+ cells and NK1.1+ cells were found to express mXCR1. Identification of mXCR1 will now allow us to study the role of this unique cytokine system in the mouse models of inflammation and immunity.